CHAIN MAIL, NOTABLY FOR PROTECTIVE EQUIPMENT
Disclosed is a chain mail constituted of a lattice of interlinked metal rings, in particular for personal protective equipment. The chain mail rings are made using a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,600 and 2,550 N/mm2, limits included.
This invention relates to the general field of chain mail, in particular for protective equipment (in particular personal protective equipment of the gloves, aprons, vests, etc. type).
TECHNOLOGICAL BACKGROUNDPersonal protective equipment for certain industries (in particular industries that use cutlery articles, for example the meat industry), or for the protection against aggressions from projectiles (bullets, shrapnel, etc.) or weapons, frequently comprise parts made of metal particles.
These metal particles consist advantageously in chain mail fabrics formed by an interlinking of metal rings.
Such personal protective equipment is appreciated in particular for its intrinsic qualities in resisting cuts and perforation.
Given the protective function sought, it is desired to obtain metal webs that have optimal safety and resistance characteristics.
These performance characteristics are for example defined in standard NF EN ISO 13998.
According to this standard, personal protective equipment with a performance level I (tested for perforation at 2.45 Joules) offers a certain degree of protection against cuts and is suitable only in situations of light work and if violent movements for cutting towards the body do not take place.
Furthermore according to this standard, personal protective equipment with a performance level II (tested for perforation at 4.9 Joules) is suitable for uses in slaughterhouses, in deboning operations and in processing industries when knives with narrow blades are used for cutting operations wherein the tip of the knife is not directed towards the body. They are also suitable when knives with wide blades are used for cutting operations wherein the tip of the knife can be directed towards the body.
Still according to this standard, the tensile strength of the rings has to be at least:
100 N +/−10 N for performance level I, and
200 N +/−10 N for performance level II.
There are also standards pertaining to weapons, for example the HOSDB Knife and Spikes standards and NIJ standard 0115.00, for the KR1/SP1, KR2/SP2, and KR3/SP3 performance levels.
For this, for example, in document FR-2 898 249, it has been proposed to produce the fabric of chain mail with rings that have an inner diameter between 3 and 3.2 mm and which are manufactured with a wire that has a diameter lower than 0.45 mm.
These chain mail rings are advantageously made of stainless steel.
However, generally, those skilled in the art consider that the techniques for manufacturing chain mails, and in particular the required operations of cutting, stamping, forming, bending and/or welding metal particles, limit the possibilities of using very hard and very resistant metals.
Therefore, steels (for example 316L, 304L austenitic) are conventionally used, whereof the characteristics of resistance and hardness are at the limit of the possibilities for cutting, forming and welding the particles that comprise the aforementioned webs.
Alongside this, a few solutions have been proposed for the supply of chain mails made from metals that make it possible to obtain webs that have resistance and hardness properties that are superior to conventional webs, or that have similar properties but whereof the weight would be less due to the use of a lesser thickness.
For example, document FR-2 898 250 describes a particular method for manufacturing a piece of protective clothing or a part of a piece of protective clothing, comprising a web of metal particles attached together, of the type of a web of interlinked metal rings, or web of metal plates attached via metal junction rings or another means.
The corresponding method consists—in a first step, using a metal or metals with a structural hardening that have not been subjected to a final heat treatment, of cutting the metal particles, form them and attached them together in order to obtain the metal web sought,—in a second step, thermally treating the metal web obtained, this in a way that is suitable for increasing the resistance and hardness characteristics of the metal particles that comprise said web,—and finally using the thermally treated metal web in order to manufacture the protective clothing sought, or in order to finalize the manufacture of this clothing.
According to another example, document WO-2013/007298 describes personal protective equipment that comprises a fabric of chain mail whereof the rings have an outer diameter between 3.98 and 4.02 mm and are manufactured with a wire whereof the diameter is between 0.47 and 0.52 mm, having a mechanical tensile strength (Rm) between approximately between 1,200 and 1,500 N/mm2.
In this document, the metal wire that comprises rings comprises steel that has an austeno-ferritic structure of standard composition, namely Fe with:
a C content not upper than 0.03% by weight;
a Mn content not exceeding 2.00% by weight;
a Si content not upper than 0.75% by weight;
a S content not upper than 0.01% by weight;
a P content not upper than 0.030% by weight;
an Ni content between 4.50% by weight and 6.50% by weight;
a Cr content between 21% by weight and 23% by weight;
an Mo content between 2.50% by weight and 3.50% by weight;
an N content between 0.15% by weight and 0.20% by weight;
with the rest being substantially Fe and accidental impurities.
This composition is practically identical to the grade 1.4462 of the standard FR EN 10088-1 (2005) or 329LN of the standard AISI.
However, document WO-2013/007298 does not disclose a chain mail whereof the performance is optimal with regards to the mechanical tensile strength (Rm) and abrasion.
These intrinsic characteristics thus do not make it possible to lower the wire diameter to lower than 0.47 mm, then generating problems of weight with the equipment.
Those skilled in the art furthermore know the risk of seeking to excessively increase the mechanical tensile strength (Rm) of the wire, under penalty of obtaining a brittle material due its low capacity for elongation at break and therefore imperfect to meet these standards.
In light of the above, it is interesting to propose new solutions for the obtaining of chain mails that have resistance and/or hardness properties that are superior to the aforementioned webs, or that have similar properties but whereof the weight would be less due to the use of a lesser thickness, even a chain mail that offers a compromise between these two objectives.
OBJECT OF THE INVENTIONThe invention aims to overcome this disadvantage of prior art by proposing a chain mail (i.e. comprised of a lattice interlinked metal rings) whereof said chain mail rings are made from a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,600 and 2,550 N/mm2, limits included, preferably between 1,750 and 2,550 N/mm2, limits included, and more preferably between 1,900 and 2,300 N/mm2, limits included.
The inventors have observed that, surprisingly and unexpectedly, despite its high mechanical tensile strength (Rm), such a wire remains not very brittle and is well suited for implementing the conventional techniques of manufacturing chain mails, and in particular conventional operations of cutting, stamping, forming, bending and/or welding of metal particles.
The rings of this chain mail are less subject to the deformations due to external mechanical aggressions during the use and maintenance (knife impacts, tensions, catching by machines in rotation, during cleaning operations in machines, etc.); they also have very high resistance to wear and tear (friction against the cutting tables, against blocks, during cleaning operations, etc.).
Such a wire also has a narrow range of mechanical tensile strength (Rm) with respect to the target value (+/−25 N advantageously), and provides consistency and repeatability to the mechanical resistance.
In addition, the inventors have shown that such a material makes it possible to obtain either a chain mail having resistance and hardness properties that are superior to the aforementioned webs, or a chain mail having similar properties but whereof the weight would be less due to the use of a lesser thickness, even a chain mail that offers a compromise between these two objectives.
Such a chain mail confers:
lightness,
resistance to deformation, and
resistance to wear and tear.
Preferably, chain mail rings are made with a stainless steel wire whereof the elongation at break is upper than 2%, preferably upper than 3%, more preferably between 3 and 3.5%.
According to a preferred embodiment, said chain mail rings are carried out with a stainless steel wire, advantageously a stainless steel wire with a two-phase structure comprised of ferrite and of austenite, comprising (even consisting of):
carbon (C) in a proportion by weight between 0.01 and 0.03%, limits included,
silicon (Si) in a proportion by weight between 0.4 and 0.6%, limits included,
manganese (Mn) in a proportion by weight between 0.7 and 0.9%, limits included,
phosphorus (P) in a proportion by weight lower than or equal to 0.03%,
sulphur (S) in a proportion by weight lower than or equal to 0.015%,
chromium (Cr) in a proportion by weight between 21 and 23%, limits included,
molybdenum (Mo) in a proportion by weight between 2.9 and 3.5%, limits included,
nickel (Ni) in a proportion by weight between 4.5 and 5.5%, limits included,
nitrogen (N) in a proportion by weight between 0.14 and 0.22%, limits included, and
iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
This invention also relates to a set for the meat industry, comprising:
personal protective equipment according to the invention, and
a cutlery article comprising a blade made from a steel whereof the mechanical tensile strength (Rm) is lower than 2200 N/mm2, and whereof the elongation at break is lower than 2%.
Such a combination provides optimal safety for the individual wearing the personal protective equipment.
This invention also relates to a method for the manufacture of a chain mail according to the invention.
This method comprises:
the supply of a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,600 and 2,550 N/mm2, limits included, and advantageously whereof the elongation at break is upper than 2%, preferably upper than 3%, more preferably between 3 and 3.5%, and
the cutting of sections in said wire, the forming and the assembling of said sections in order to obtain said chain mail.
DETAILED DESCRIPTION OF THE INVENTIONThis invention as such relates to a chain mail which is in particular suited for personal protective equipment which is intended in particular:
for the meat industry, in order to provide protection of the hand of a person who uses cutting or sharp tools, or
for protection against aggressions by projectiles (bullets, shrapnel, etc.) or weapons.
Such personal protective equipment is for example described in document FR-2 898 249.
For example, a glove comprises a hand portion extended by a portion in the form of a cylindrical sleeve intended cover the wrist of the user. This portion can be extended by an extension that forms a protective sleeve of the forearm or of the arm.
This glove can furthermore be equipped with a tightening system on the wrist in order to provide an effective hold on the hand.
This personal protective equipment comprises at least one portion made of chain mail.
The chain mail is constituted by a lattice of interlinked metal rings, also referred to as “chain mail fabric”.
The metal rings are advantageously interlinked conventionally, preferably chain mail of the English type.
According to the invention, the chain mail rings are made from a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,600 and 2,550 N/mm2, limits included, preferably between 1,750 and 2,550 N/mm2, limits included, and more preferably between 1,900 and 2,300 N/mm2, limits included, and even more preferably between 2,000 and 2,200 N/mm2, limits included.
This stainless steel wire also advantageously has an elongation at break that is upper than 2%, preferably upper than 3%, more preferably between 3 and 3.5%.
Such a pair of values for the wire (mechanical tensile strength (Rm)/elongation at break) constitutes a particularly interesting compromise between the hardness and the deformability, for the protection with regards in particular to the phenomena of perforation and for the manufacture of the chain mail.
“Stainless steel” means in particular the family of steels (iron and carbon alloys) to which is substantially added chromium which provokes the forming of a protective layer of chromium oxide which provides these steels with their inoxydability.
Other elements can be added, in particular:
nickel which improves the mechanical properties in general and ductility in particular,
molybdenum or titanium which improve the stability of the alloy for temperatures other than the ambient temperature, as well as
elements with a high melting point such as vanadium and tungsten.
The inventors have identified a particular stainless steel, whereof the specific chemical composition generates the aforementioned mechanical resistance and allows for the production of a wire that is particularly suited for the production of chain mail rings.
In this respect, chain mail rings are advantageously made from a stainless steel wire comprising (even consisting of):
carbon (C) in a proportion by weight between 0.01 and 0.03%, limits included,
silicon (Si) in a proportion by weight between 0.4 and 0.6%, limits included,
manganese (Mn) in a proportion by weight between 0.7 and 0.9%, limits included,
phosphorus (P) in a proportion by weight lower than or equal to 0.03%
sulphur (S) in a proportion by weight lower than or equal to 0.015%
chromium (Cr) in a proportion by weight between 21 and 23%, limits included,
molybdenum (Mo) in a proportion by weight between 2.9 and 3.5%, limits included,
nickel (Ni) in a proportion by weight between 4.5 and 5.5%, limits included,
nitrogen (N) in a proportion by weight between 0.14 and 0.22%, limits included, and
iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
More preferably, the meshes are made with a stainless steel wire comprising (even consisting of):
carbon (C) in a proportion by weight between 0.012 and 0.021%, limits included,
silicon (Si) in a proportion by weight between 0.46 and 0.59%, limits included,
manganese (Mn) in a proportion by weight between 0.76 and 0.88%, limits included,
phosphorus (P) in a proportion by weight between 0.021 and 0.027%, limits included,
sulphur (S) in a proportion by weight between 0.0005 and 0.0009%, limits included,
chromium (Cr) in a proportion by weight between 22.09 and 22.37%, limits included,
molybdenum (Mo) in a proportion by weight between 3.15 and 3.27%, limits included,
nickel (Ni) in a proportion by weight between 5.18 and 5.32%, limits included,
nitrogen (N) in a proportion by weight between 0.162 and 0.20%, limits included, and
iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
Such a stainless steel advantageously includes a two-phased structure comprised of ferrite and of austenite, also referred to as “duplex steel”.
Such a stainless steel is also designated as belonging to the family of austeno-ferritic steels.
Various fabrics made from chain mail can as such be manufactured using this stainless steel for the production of personal protective equipment.
According to a first embodiment, the chain mail rings have an outer diameter between 3.8 mm and 4.2 mm, limits included, and are made from stainless steel wire whereof the diameter is between 0.38 mm and 0.6 mm, limits included.
In this case, preferably, the rings are made from stainless steel wire whereof the diameter is between:
0.38 mm and 0.5 mm, limits included, preferably between 0.38 mm and 0.45 mm, limits included; or
0.45 mm and 0.6 mm, limits included, preferably between 0.5 mm and 0.6 mm, limits included.
Without being limiting, the rings comprise a tensile strength that is upper than 300 N, with preferably:
a tensile strength between 300 and 400 N, carried out with a wire of a diameter of 0.4 mm and
a tensile strength between 500 and 600 N, carried out with a wire of a diameter of 0.5 mm.
In this framework, for the carrying out of a glove or of an apron for example, the chain mail rings have an outer diameter of 4 mm, and are made from stainless steel wire whereof the diameter is 0.4 mm.
The wire then has a mechanical tensile strength (Rm) of about 2100 N/mm2; and the rings have a tensile strength of about 350 N.
Such personal protective equipment then meets a performance level I (tested for perforation at 2.45 Joules according to the standard NF EN ISO 13998).
According to another example, for the carrying out of an apron, the chain mail rings have an outer diameter of 4 mm, and are made from stainless steel wire whereof the diameter is 0.5 mm.
The wire then also has a mechanical tensile strength (Rm) of 2100 N/mm2; and the rings have a tensile strength of about 600 N.
Such personal protective equipment then meets a performance level II (tested for perforation at 4.9 Joules according to NF EN ISO 13998).
According to a second embodiment, the rings have an outer diameter between 6.5 mm and 8 mm, limits included, and are made from stainless steel wire whereof the diameter is between 0.6 mm and 1 mm, limits included.
Such a chain mail is in particular interesting in ballistic uses, in particular in the form of a weapon pack added to a ballistic solution.
In this case, this chain mail is used in combination with a multilayer complex of technical fabric (aramid fibres, high-tenacity polyester, etc.).
The rings of this chain mail can also be carried out with a wire with a reduced diameter, while still retaining suitable performance qualities. The rings then advantageously comprise a usual outer diameter but an increased inner diameter.
Such a chain mail then comprises a weight that is substantially reduced due to the synergy between:
the reduction in the weight of each ring, but also
the decrease in the density of the rings per surface unit.
Generally, the invention also relates to a set for the meat industry, comprising:
aforementioned personal protective equipment, and
a cutlery article (in particular a knife) comprising a blade made from a steel whereof the mechanical tensile strength (Rm) is lower than 2,200 N/mm2, and whereof the elongation at break is lower than 2%.
With such a pair, the inventors observed optimal protection of the individual.
Generally, the various fields according to the invention have limits included.
Advantageously, this stainless steel can indeed be worked through the implementation of a conventional method of manufacturing chain mail, that uses conventional machines.
Preferably, the manufacture of a chain mail according to the invention comprises the following steps:
the supplying of a stainless steel wire such as described hereinabove (also referred to a wire rod”), and
the cutting of sections in said wire, the forming and the assembling of said sections in order to obtain said chain mail.
Claims
1-12. (canceled)
13. Chain mail, i.e. constituted of a lattice of interlinked metal rings, wherein said chain mail rings are made from a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,600 and 2,550 N/mm2, limits included.
14. Chain mail according to claim 13, wherein said chain mail rings are made from a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,900 and 2,300 N/mm2, limits included.
15. Chain mail according to claim 13, wherein said chain mail rings are made from a stainless steel wire whereof the elongation at break is upper than 2%, preferably upper than 3%, more preferably between 3 and 3.5%.
16. Chain mail according to claim 13, wherein said chain mail rings are made from a stainless steel wire comprising:
- carbon (C) in a proportion by weight between 0.01 and 0.03%, limits included,
- silicon (Si) in a proportion by weight between 0.4 and 0.6%, limits included,
- manganese (Mn) in a proportion by weight between 0.7 and 0.9%, limits included,
- phosphorus (P) in a proportion by weight lower than or equal to 0.03%,
- sulphur (S) in a proportion by weight lower than or equal to 0.015%,
- chromium (Cr) in a proportion by weight between 21 and 23%, limits included,
- molybdenum (Mo) in a proportion by weight between 2.9 and 3.5%, limits included,
- nickel (Ni) in a proportion by weight between 4.5 and 5.5%, limits included,
- nitrogen (N) in a proportion by weight between 0.14 and 0.22%, limits included, and
- iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
17. Chain mail according to claim 16, wherein said chain mail rings are made from a stainless steel wire comprising:
- carbon (C) in a proportion by weight between 0.012 and 0.021%, limits included,
- silicon (Si) in a proportion by weight between 0.46 and 0.59%, limits included,
- manganese (Mn) in a proportion by weight between 0.76 and 0.88%, limits included,
- phosphorus (P) in a proportion by weight between 0.021 and 0.027%, limits included,
- sulphur (S) in a proportion by weight between 0.0005 and 0.0009%, limits included,
- chromium (Cr) in a proportion by weight between 22.09 and 22.37%, limits included,
- molybdenum (Mo) in a proportion by weight between 3.15 and 3.27%, limits included,
- nickel (Ni) in a proportion by weight between 5.18 and 5.32%, limits included,
- nitrogen (N) in a proportion by weight between 0.162 and 0.20%, limits included, and
- iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
18. Chain mail according to claim 13, wherein said chain mail rings are made from a stainless steel wire with a two-phased structure comprised of ferrite and of austenite.
19. Chain mail according to claim 13, wherein said chain mail rings have an outer diameter between 3.8 mm and 4.2 mm, limits included, and are made from stainless steel wire whereof the diameter is between 0.38 mm and 0.6 mm, limits included.
20. Chain mail according to claim 19, wherein said rings are made from stainless steel wire whereof the diameter is between:
- 0.38 mm and 0.5 mm, limits included, preferably between 0.38 mm and 0.45 mm, limits included; or
- 0.45 mm and 0.6 mm, limits included, preferably between 0.5 mm and 0.6 mm, limits included.
21. Chain mail according to claim 13, wherein said rings have an outer diameter between 6.5 mm and 8 mm, limits included, and are made from stainless steel wire whereof the diameter is between 0.6 mm and 1 mm, limits included.
22. Chain mail according to claim 13, wherein said chain mail rings are made from a stainless steel wire whereof the mechanical tensile strength (Rm) is between 1,900 and 2,300 N/mm2, limits included,
- wherein said chain mail rings are made from a stainless steel wire whereof the elongation at break is upper than 2%, preferably upper than 3%, more preferably between 3 and 3.5%,
- wherein said chain mail rings are made from a stainless steel wire comprising:
- carbon (C) in a proportion by weight between 0.01 and 0.03%, limits included,
- silicon (Si) in a proportion by weight between 0.4 and 0.6%, limits included,
- manganese (Mn) in a proportion by weight between 0.7 and 0.9%, limits included,
- phosphorus (P) in a proportion by weight lower than or equal to 0.03%,
- sulphur (S) in a proportion by weight lower than or equal to 0.015%,
- chromium (Cr) in a proportion by weight between 21 and 23%, limits included,
- molybdenum (Mo) in a proportion by weight between 2.9 and 3.5%, limits included,
- nickel (Ni) in a proportion by weight between 4.5 and 5.5%, limits included,
- nitrogen (N) in a proportion by weight between 0.14 and 0.22%, limits included, and
- iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
23. Chain mail according to claim 22, wherein said chain mail rings are made from a stainless steel wire comprising:
- carbon (C) in a proportion by weight between 0.012 and 0.021%, limits included,
- silicon (Si) in a proportion by weight between 0.46 and 0.59%, limits included,
- manganese (Mn) in a proportion by weight between 0.76 and 0.88%, limits included,
- phosphorus (P) in a proportion by weight between 0.021 and 0.027%, limits included,
- sulphur (S) in a proportion by weight between 0.0005 and 0.0009%, limits included,
- chromium (Cr) in a proportion by weight between 22.09 and 22.37%, limits included,
- molybdenum (Mo) in a proportion by weight between 3.15 and 3.27%, limits included,
- nickel (Ni) in a proportion by weight between 5.18 and 5.32%, limits included,
- nitrogen (N) in a proportion by weight between 0.162 and 0.20%, limits included, and
- iron (Fe), in a proportion by remaining weight in order to obtain 100%, except for accidental impurities.
24. Chain mail according to claim 23, wherein said chain mail rings are made from a stainless steel wire with a two-phased structure comprised of ferrite and of austenite.
25. Chain mail according to claim 24, wherein said chain mail rings have an outer diameter between 3.8 mm and 4.2 mm, limits included, and are made from stainless steel wire whereof the diameter is between 0.38 mm and 0.6 mm, limits included.
26. Personal protective equipment comprising at least one portion made of chain mail according to claim 13.
27. Set for the meat industry, comprising:
- personal protective equipment according to claim 26, and
- a cutlery article comprising a blade made from a steel whereof the mechanical tensile strength (Rm) is lower than 2,200 N/mm2, and whereof the elongation at break is lower than 2%.
28. Personal protective equipment comprising at least one portion made of chain mail according to claim 14.
29. Personal protective equipment comprising at least one portion made of chain mail according to claim 15.
30. Personal protective equipment comprising at least one portion made of chain mail according to claim 16.
31. Personal protective equipment comprising at least one portion made of chain mail according to claim 17.
32. Personal protective equipment comprising at least one portion made of chain mail according to claim 18.
Type: Application
Filed: Feb 18, 2016
Publication Date: Mar 8, 2018
Inventors: Philippe JAUNAULT (Pornic), Franck BENETEAU (Champtoce sur Loire)
Application Number: 15/551,697
